This invention relates generally to the field of tracheal intubation. More, particularly, this invention relates to an apparatus that allows for improved orotracheal intubation of patients.
Tracheal intubation is placing a tube into the trachea. The most common tracheal intubation is orotracheal intubation where an endotracheal tube is passed through the mouth, through the larynx, and into the trachea.
Tracheal intubation is performed in various medical conditions. One example is a comatose or intoxicated patient who is unable to protect their airways. In such patients, the throat muscles may lose their tone so that the upper airways obstruct or collapse and air can not easily enter into the lungs. Furthermore, protective airway reflexes such as coughing and swallowing, which serve to protect the airways against aspiration of secretions and foreign bodies, may be absent. With tracheal intubation, airway patency is restored and the lower airways can be protected from aspiration. Another example is a patient undergoing general anesthesia. In anesthetized patients, spontaneous respiration may be decreased or absent due to the effect of anesthetics, opiods or muscle relaxants. To enable mechanical ventilation, an endotracheal tube is often used, although there are alternative devices such as face masks or laryngeal mask airways. Other conditions wherein orotracheal intubations may be performed are during diagnostic manipulation of the airways, such as bronchoscopy, or endoscopic operative procedures to the airways, such as laser therapy or stenting of the bronchi. Oratracheal intubation are also performed during intensive care for patients who require respiratory support, and emergency medicine, particularly for cardiopulmonary resuscitation.
Tracheal intubation is usually performed by direct laryngoscopy (conventional technique), in which a laryngoscope is used to obtain a view of the vocal cords. A tube is then inserted under direct vision through the vocal cords. This technique can usually only be employed if the patient is comatose (unconscious), under general anesthesia, or has received local or topical anesthesia to the upper airway structures (e.g., using a local anesthetic drug such as lidocaine).
There are many types of laryngoscopes. The main categories are those for adult use and those for child use. The blade may be curved, e.g., the Macintosh; straight, e.g., the Miller blade; at a 120 degree angle, as in the polio blade; or with a hinged blade tip seen in the McCoy laryngoscope, with is commonly used in managing difficult intubations. The handle may be short to allow use when there is limited space, commonly seen during a rapid sequence induction of an obese individual where there is less room for both cricoid pressure application and performing laryngoscopy. The fibreoptic intubating laryngoscope is also used for intubation (its other uses including examination of the airway and bronchial tree). Fiberoptics are used when intubation is required in the presence of upper airway obstruction, e.g., oral abscess, tumor, angioedema, or limited neck movement. In these circumstances, the airways are carefully anesthetised with local anaesthetic and vasoconstrictor drugs before performing awake intubation.
In the typical orotracheal intubation procedure (FIGS. 1A and 1B), the blade is inserted into the right corner of the patient's mouth 1. If a curved Macintosh blade is used, the flange will push the tongue to the left side of the oropharynx. After visualization of the arytenoids, the epiglottis 4 is directly lifted with the straight blade or indirectly lifted with the curved blade. The larynx 3 is then exposed by pulling the handle in the direction that it points, i.e., 90° to the blade 2. In normal patients, the vocal cords should then come into view. The tube is then advanced until the cuff disappears below the vocal cords. Correct tube placement is about 2 cm above the carina. The cuff is then inflated, an oropharyngeal airway or bite block is inserted and auscultated to verify bilateral lung expansion.
Most intubations are uncomplicated and straightforward. In patients with known intubation difficulties, measures can be taken prior to the intubation procedure to mitigate such difficulties. However, certain unforeseen circumstances can arise which can make an airway difficult to intubate, e.g., placement of vocal cords in the patient's voice box. Currently, none of the blades on the market provides a good view of the vocal cords if they are located in the vocal box more anterior relative to normal vocal cords. In such patients, using a conventional blade would cause the tube to slip into the esophagus, and the cords, which serve as an anatomical mark for proper placement of the endotracheal tube, will be out of view, i.e., located anterior to the tip of the blade. With a tube-shaped blade, the tubular shape of the blade will slide between the vocal cords, thus preventing the cords from being lifted anteriorly, as with a conventional blade, and making placement of the endotracheal tube easier or possible.
The present invention is an apparatus intended to improve the ease of intubating a patient and help overcome the problems that currently create difficulties for orotracheal intubation via traditional laryngoscope blades.